There is an increasing need to perform various types of diagnostic tests on animals of all types. For example, animal species such as bovinae, equidae, caprinae, suidae and a variety of poultry and other ayes (whether domestic or wild) are reservoirs of human pathogens. Organizations and veterinary professionals that are tasked with monitoring the health of the animals and the safety of the human food supply need timely and accurate information about the health status of animals. Furthermore, other sensitive diagnostic tests are available or in development for assessing metabolic and reproductive status of animals. These tests require obtaining precise and accurate small volumes of fluid or tissue from animals.
In the case of farm animals, such as cow (for example), the ability to obtain precise (especially small) volumes (e.g., less than 1000 μL and especially less than 100 μL) of fluid or tissue samples (for example, a blood sample) in one step without the need for additional pipetting steps is currently not possible. Conventional techniques for obtaining samples often require more than one person, as well as sample movement between different locations using a combination of sampling devices and pipetting devices. In some cases, this expected delay between obtaining a large, imprecise, volume of blood and subsequent sub-sampling requires that an anticoagulant be added to the sample to prevent clotting until the sub-sampling is possible. Anticoagulants can interfere with some diagnostic assays. The sampling approach used in domestic and wild animals may also create challenges for the clinician, including the possibility of being dangerous to the well-being of the clinician. There are various types of needles, lancets or other piercing devices that may be handled as individual components or attached to a syringe and inserted into a vessel proximal to the skin of the animal. In some instances a needle is inserted and then a separate tube, or similar collection device is attached to the needle and used to collect the sample in volumes ranging from 3 to several 100 milliliters, often with an anticoagulant. This sample is then transported to a nearby area (e.g., a laboratory) where a precise volume of the sample is removed from the larger sample for application in a variety of assay platforms.
With the tremendous advances in the sensitivity of a variety of diagnostic tests there is a real need for a one step process that allows animal health care professionals to obtain precise and accurate small volumes of fluid or tissue in one step (e.g., 10-100 μL), without the need for additional pipette sub-sampling and in some instances without the use of anticoagulant.